Home ADB Microbridge Android + Arduino + USB Host + Simple Digital Output

Android + Arduino + USB Host + Simple Digital Output

Posted by michael on May 2, 2012 in ADB Microbridge, Android, Arduino, Tutorials | 18 comments

This worked for me.

Simplest possible digital output with Android and Arduino. This article will discuss the bare minimal requirements for development of an Android USB digital output device. The goal is to demonstrate the easiest possible use of the technology. For additional background information on Android development, Arduino, and MicroBridge, check out these links:

Android Developer’s Guide
Getting Started with Arduino
Microbridge

Getting Started

First, make sure you have setup the development environments for Arduino and Android:

Arduino IDE
Android SDK

Hardware

Parts needed:

Android Device (1.6+)
3x LED Lights
3x 330 ohms resistors
Breadboard
Power supply
Hook-up wire
Android ADK Board*
– OR –
Arduino compatible and USB Host shield

*Supported boards include:

Google ADK board, Freeduino ADK board , Seeed Studio ADK board, and DIY Drones ADK board

Assembly

Connect the 330 ohm resistors in series with the anodes of the LEDs to the desired digital output pins, and the cathodes of the LEDs to ground. The example uses digital pins 2, 3, and 4, but can be used with any IO pin that doesn’t interfere with the SPI communication with the USB Host Board. For most boards, these are pins 10 – 14. The resistors, in this case, are being used to prevent current overdraw to the LEDs. Here is a diagram of the completed circuit (created with Fritzing):

Software

Arduino Firmware

Next, upload the Arduino sketch to the microcontroller. The sketch uses the Microbridgeimplementation by Niels Brouwers. Microbridge uses Android Debug Bridge (ABD) forwarding over TCP, rather than the official Google Android ADK. You can checkout the source for the Arduino sketch from Github, or just copy and paste the following into the Arduino IDE.

#include <SPI.h> #include <Adb.h> #define LEDcount 3 Connection * connection; long lastTime; //Array of state of LEDs uint8_t LEDState[LEDcount]; // Event handler for shell connection; called whenever data sent from Android to Microcontroller void adbEventHandler(Connection * connection, adb_eventType event, uint16_t length, uint8_t * data) { // In this example Data packets contain three bytes: one for the state of each LED if (event == ADB_CONNECTION_RECEIVE) { int i; for (i = 0; i < LEDcount; i++) { if(LEDState[i] != data[i]) { digitalWrite(i+2, data[i]); // Change the state of LED Serial.println(data[i],DEC); // Output debugging to serial LEDState[i] = data[i]; // Store the State of LED } } } } void setup() { int i; for (i = 0; i < LEDcount; i++) { pinMode(i+2,OUTPUT); // Set pins as output LEDState[i] = 0; // Init state to 0 } // Init serial port for debugging Serial.begin(57600); // Init the ADB subsystem. ADB::init(); // Open an ADB stream to the phone's shell. Auto-reconnect. Use any unused port number eg:4568 connection = ADB::addConnection("tcp:4568", true, adbEventHandler); } void loop() { // Poll the ADB subsystem. ADB::poll(); }

Android App

Finally, install the Android Demo application onto the device. You can either download the pre-built .apkor checkout the source from Github:

git clone git://github.com/mitchtech/android_adb_simple_digital_output.git

Finally upload the app to the device (or browse to this page on the device and download the apk above). Connect the Android device to the USB Host board/shield, and start up the app.

18 Comments

aditya pratap singh
July 26, 2012

great example i have successfully implemented this example. actually i am making android application in which when phone rings then led blink. i have implemented the phonelistener class it is detecting the state of the phone but its not able to send the byte using this code

try {
// Send the state of each LED to ADK Main Board as a byte
mServer.send(new byte[] { (byte) mLedData1});
} catch (IOException e) {
Log.e(TAG, “problem sending TCP message”, e);
}

i am using the same arduino code that u have used to ledblink using button. can pls help me. i struggling a lot.

reply
Ahmed
October 4, 2012

I think the Arduino code is not the one for this example? Either way, I made the code on my own and used your Android version. Works like a charm!

Thanks a lot for your guide!

reply
- Mahmoud Shahin
  October 6, 2012
  
  Can you help me ahmed i have some errors in line 18 of the arduino code
  connection = ADB::addConnection(“tcp:4568″, true, adbEventHandler);
  i don’t what is this error ??
  
  reply
  - Ahmed
    October 7, 2012
    
    Hi! Did you use the Arduino code on this page? because I’m fairly sure it does not match this example.
    
    Anyways, what does the Arduino say about the error?
    
    reply
  - Ahmed
    October 7, 2012
    
    I think I know what the error is! When you copy-paste the code into the Arduino IDE, the ‘ ” ‘ & ‘ – ‘ characters are not copied correctly. So you’ll have to rewrite them.
    
    The IDE probably tells you that there’s a stray / error, right?
    
    reply
    - Mahmoud Shahin
      October 7, 2012
      
      What arduino version you use ( 1.0.1 or 1.0 or 0.022)?
      which library you used ? there are a lot of libraries ??
      to know also i am using arduino mega adk …
      the error in line 18
      connection = ADB::addConnection(“tcp:4568″, true, adbEventHandler);
      thanks a lot for your answer ..
      
      reply
      - Mahmoud Shahin
        October 7, 2012
        
        Ahmed ,
        yes there are a stray error
        what is the solution ?
    - Mahmoud Shahin
      October 7, 2012
      
      to be specific
      how can i change ” – ” written in line 23
      if ((millis() – lastTime) > 20)
      ??????????
      
      reply
    - michael
      October 22, 2012
      
      Copying and pasting the code directly from the website seemed to grab extra characters, so I have enclosed it within a github gist. It should now work correctly without stray ‘\’s now!
      
      That was indeed the issue, thanks for pointing out the easy fix!
      
      reply
- Gab Pesieto
  October 28, 2012
  
  ahmed can you send me the arduino code for this tutorial? thanks
  email: richard.pesieto@yahoo.com
  \
  
  reply
  - Ahmed
    October 29, 2012
    
    Hi!
    
    Michael changed code to the one relavant for this example. You can refer to his in case you are using 3 LEDs.
    
    I’ll send you a simpler version which uses only one LED as a proof of operation
    
    reply
Antonis Kanaris
December 4, 2012

Hello.The adb work with usb host shield 2.0 and arduino duemilanove?I try but mine no work.No errors.When put button led application no flash.What libraries i must use the default microbridge?

reply
alcibiades
December 8, 2012

the code is correct but you need to open de monitor serial in arduino IDE and active the NL&CR so i work myself

reply
hanaa
December 26, 2012

i have downloaded android application on mobile and uploaded arduino code there were no errors, but nothing happen and on arduino serial menitor that is error appear “Error: OSCOKIRQ failed to assert”what can i do ?
thanks alot

reply
hanaa
December 26, 2012

i have downloaded android code on mobile and upload arduino code on mega there were no erros , but nothing happen and when running arduino serial menitor thar error appear “Error: OSCOKIRQ failed to assert”
what can i do?
thanks

reply
AL
February 19, 2013

Hi I use Meka2560 ADK i’m download source code burn to board and android device it not error but unusable same VIDEO

reply
jean
April 20, 2013

hi, I’m new to Arduino.Instead of using the USB shield, i have an Arduino Uno and a bluetooth Wireless TTL Transceiver Module. Is it possible to use the same Arduino sketch and the same apk file to complete this circuit?

reply
Joms
May 7, 2013

I have tried this with an Arduino Mega 2560 ADK… I have used the inbuilt USB of the board to communicate with the Android device…No errors But No output

reply